Device for directing light beams, illustration device, method for producing a device and an illustration device

ABSTRACT

A device for directing light beams is proposed, comprising a translucent substrate, and a light-directing structure on at least a portion of the substrate, wherein the light-directing structure comprises a substantially transparent material, which is arranged in a pattern on the substrate in such a way that the light-directing structure comprises at least one optical prism.

PRIOR ART

The invention relates to a device for directing light beams, consistingof a translucent substrate, on one or both sides of whichlight-directing structures are formed.

A device of this kind is known, for example, from publishedspecification US 2006/0 279 036 A1, which among other things describes aproduction method for optical films, wherein a first liquid material isarranged on an optical film, and wherein a second liquid material isarranged in interstices of the first liquid material. Disadvantageously,with this production method no asymmetrical structures can be produced,so that production of optical prisms, and in particular of Fresnelstructures, is impossible.

Also, from published specification DE 10 2006 003 310 A1, a method ofproducing a lenticular image, and a lenticular image, are known, lensmaterial being applied in layers to a substrate. No method of producingoptical prisms is given in this published specification.

Also, for example, in the prior art, window images which are produced indecorative form from glass or plastic or gel are known. Such windowimages are transparent and fully or partially coloured. They have afunction as spectral filters. They have no optical function.

Window panes and cladding panels containing internal or externallamellar structures which act as sun protection are also known. Forbalconies, terraces and conservatories, panel materials structured inmany different ways are also used for visual privacy and protection fromglare. Roller blinds in different versions for protection from sun arealso known. They are partly coloured and also used as filters.

Skylights in the upper part of a window or room light the interior ofthe room, and linear wedge-shaped prisms can also be added to them, sothat they direct daylight deep into the interior of the room.

Films of which the surfaces are equipped on one side with even or unevenoptically acting structures are also known. These are used for directinglight and reducing glare, and can also generate enlarging or holographiceffects. However, such structures are partly designed with equal,repeating patterns.

Also, lenses of all kinds, in concave, convex, spherical or asphericalform, are known. Also, lenses, for example spectacle lenses, partialareas of which have a different light-refracting effect, are known.Also, free-form lenses produced by the injection moulding method, witharbitrary light deflection, are known. Also, so-called Fresnel lenses infilm form, which emulate a lens or prism in miniaturised circular orlinear structures to save space, are known.

From DE 10 2005 039 113 A1, attaching cylindrical lenses to a substrateby printing methods is known. Generating microlenses on substrates bymicrojet printing methods is also known.

DISCLOSURE OF THE INVENTION

Starting from this prior art, the invention is based on the object ofcreating a device for directing light beams, it being possible to formsaid device by simple means on a substrate, and to use said device inmany ways to direct light in different ways.

To achieve this object, a device for directing light beams is proposed,comprising a translucent substrate, and a light-directing structure onat least a portion of the substrate, wherein the light-directingstructure comprises a substantially transparent material, which isarranged in a pattern on the substrate in such a way that thelight-directing structure comprises at least one optical prism.

The device according to the invention has the advantage, compared withthe prior art, that on the one hand it can be produced in acomparatively inexpensive, quick and flexibly modifiable way by aprinting method, and on the other hand, by means of the optical prism,multiple different optical effects, which are impossible with the simplelenses named in the prior art, can be achieved. Production of an opticalprism has, for example, the advantage, compared with simple lenses whichare used only to collect or scatter light beams, that a light beam whichpasses through the optical prism is refracted depending on wavelength,and thus, in addition to the enlarging or reducing effect which iscaused by the light-directing structure, a special colour and/orbrightness effect can also be achieved with the light-directingstructure. For example, a light beam which passes through thelight-directing structure of the device according to the invention isexpanded into its spectrum. It is also possible to achieve a very widevariety of optical effects in a comparatively simple way, by aparticular arrangement and/or form of multiple optical prisms. Inparticular, only the characteristic optical parameters, the position andthe alignment of the individual optical prisms must be chosencorrespondingly. For example, it is provided that the light-directingstructure comprises an optical lens, and in particular a Fresnelstructure, which is formed from the at least one optical prism, and inparticular from multiple optical prisms. Thus, advantageously, byarranging multiple optical prisms in the form of a Fresnel structure, itis possible to achieve an optical lens which compared with the prior artis of a substantially smaller height perpendicularly to a plane ofprincipal extension of the substrate. A Fresnel structure in the senseof the present invention preferably comprises a set of concentricsections (e.g., annular sections), wherein each section includes orconsists of a different prism. For each of these zones, the overalthickness of the lens is decreased, effectively chopping the continuoussurface of a conventional lens into a set of surfaces of the samecurvatures with discontinuities between them, for instance. A Fresnelstructure enables the construction of lenses of large aperture and shortfocal length without the weight and volume of material that would berequired in conventional lens design. Consequently, a Fresnel lens ismuch thinner and thus passing more light compared to conventionallenses. The light-directing structure is preferably arranged on one orboth sides of the substrate. The substrate can be in any form, forexample in the form of a glass and/or plastic sheet or in the form of afilm. A substantially transparent material in the sense of the presentinventions preferably comprises a material allowing light to pass atleast partly through the material. In particular, the substantiallytransparent material consists of an optical transparent material whichallows much of the light that falls on them to be transmitted, withlittle being deflected. At least light waves with wavelengths in therange of the visible spectrum (e.g. wavelengths between 380 and 750nanometers) particularly pass the transparent material with averagetransmittance rates higher than 80%, preferably higher than 90% andparticularly preferably higher than 95%. The material could also be atranslucence material only allowing light to pass through diffusely, forinstance.

According to a preferred embodiment of the present invention, it isprovided that the light-directing structure comprises multipleapplications which are printed on the substrate, and which include orconsist of the transparent material. Advantageously, the light-directingstructure, and in particular the at least one optical prism, are builtup by individual applications, which in particular are printedsimultaneously or sequentially onto the substrate. In particular, theapplications are applied to the substrate individually or in spots. Thusadvantageously, comparatively complex light-directing structures caneasily be built up, it being necessary to specify only the sizes andpositions of the individual applications on the substrate. This can bedone, for instance, by a computer or other processor (which may be partof the systems herein) programmed and/or programmable with apredetermined set of printing instructions. The production cost isconsiderably reduced in this way. The applications are preferablyarranged adjacently or one above the other in a parallel plane to theplane of principal extension of the substrate. In this way, from theapplications, any desired three-dimensional structures, which havespecified optical properties, can be built up on the substrate. Theapplications preferably overlap. At least partial stacking of theapplications perpendicularly to the plane of principal extension makesit possible to build up a light-directing structure which is higher thanthe diameter of the individual applications. The individual applicationseither remain within the light-directing structure as discreteapplications or are joined to adjacent applications, according tochoice.

According to a preferred embodiment of the present invention, it isprovided that the applications comprise particles of the transparentmaterial, droplets of the transparent material and/or linearly formedstrips of the transparent material, the applications preferablycomprising droplets of the transparent material which may be cured byultraviolet radiation. Forming the application as droplets makespossible, for example, comparatively fine and precise buildup of thelight-directing structure, whereas forming the applications as strips,for example, makes possible comparatively fast, inexpensive productionof a larger light-directing structure. In general, any of the individualparticles, droplets, and/or strips may be substantially microscopic insize (e.g., they have a diameter or other largest dimension that issmaller than about 0.10 mm, and more preferably smaller than about 0.05mm, or even smaller than about 0.03 mm).

According to a preferred embodiment of the present invention, it isprovided that the multiple applications have different and/orsubstantially equal radii, in particular the optical prism being formedof multiple applications of different radii or from multipleapplications of equal radii. Advantageously, for example, a wedge-shapedprism is built up of multiple applications, in particular droplets,which all have the same radius. At the broad end of the prism, multipleapplications are stacked one above the other, whereas, no applicationsstacked one above the other are arranged at the narrow end of the prism.The number of applications stacked one above the other preferably fallssuccessively from the broad end of the prism to the narrow end of theprism, so that a functional face which is inclined relative to thesubstrate results. Advantageously, with this buildup, no applications ofdifferent diameters have to be printed on. Alternatively, it isconceivable that a wedge-shaped prism is built up with applications, inparticular droplets, of different radii. In this case the broad end ofthe prism is formed by one application of greater radius, and thenarrower end of the prism is formed by one application of smallerradius. The radius of the applications preferably falls successivelyfrom the broad end of the prism to the narrow end of the prism.Advantageously, with this buildup, the prism can be producedcomparatively quickly, since an application does not have to be placedseveral times at the same location.

According to a preferred embodiment of the present invention, it isprovided that the applications are placed on a planar periphery of thesubstrate, the applications preferably each having an approximatelyhemispherical curvature, which projects from the substrate. The planarperiphery comprises, in particular, a surface of the substrate. Theradius of curvature may be generally constant across the application,varying, or a combination.

According to a preferred embodiment of the present invention, it isprovided that the optical prism has at least one functional face (whichis e.g. a face that performs the function of breaking light waves independency of the wave lengths of the light waves) which is inclinedrelative to the substrate, and which in particular is formed on a sideof the optical prism facing away from the substrate perpendicularly tothe plane of principal extension, two adjacent optical prisms preferablyhaving different angles between the respective functional face and thesubstrate. The optical prism is preferably wedge-shaped, the surfacewhich faces away from the substrate and is slightly inclined relative tothe substrate being provided as a functional face to refract the lightbeams. The light-directing structure comprises, in particular, multipleoptical prisms, and the angles between the functional faces of themultiple optical prisms and the substrate vary. In this way, from themultiple optical prisms, preferably Fresnel structures are generated.

According to a preferred embodiment of the present invention, it isprovided that the light-directing structure consists of multipleelements, each element consisting of multiple optical prisms and/orapplications. Preferably, each element forms a partial prism, a partiallens and/or another specified optical system, the elements preferablybeing deposited or printed next to each other or in each other on thesubstrate, in such a way that the elements together form thelight-directing structure in the form of the Fresnel structure, opticalprism and/or optical lens.

According to a preferred embodiment of the present invention, it isprovided that the multiple elements are deposited next to each other onthe substrate in such a way that together they form a commonlight-directing structure in the form of a prism, a lens or a Fresnelstructure. In particular, on the surface of the substrate, theminiaturised transparent, or if required coloured and translucent,light-directing structures are arranged, these light-directingstructures consisting of multiple preferably miniaturised elements, eachelement consisting of multiple droplets, which are deposited on thesubstrate with a planar periphery, and the approximately hemisphericalcurvature of which projects from the substrate, the droplets havingdifferent or equal radii, so that each element, with the multipledroplets, forms a miniaturised partial prism or a partial lens oranother specified optical system, and so that the droplets consist of atranslucent or transparent material.

Preferably, the miniaturised transparent or coloured and translucentstructures are arranged on the surface of the substrate, thesestructures including or consisting of multiple miniaturised elements(e.g., miniaturised elements that may be in adjoining contact with eachother as depicted herein). Each of these elements in turn consists ofmultiple droplets of different diameter, so that the result is athree-dimensional geometrical shape which has a light-refracting effect.The totality of the elements preferably forms the structure which causesa corresponding light direction. Because these elements and thus thewhole structure are entirely or partly coloured and translucent, arecognisable overall motif can be formed for example. For example, themicrostructures in the form of droplets of different sizes result inplano-convex optical elements, which in turn are combined into complexmicrostructures. In this case the punctiform structures, in particular,are an elementary part of the light direction. Thus surfaces which havea partially different, but in combination a combined effect on light canbe built up. The geometrical arrangement figure on the substrate can becombined into circles, ovals, curves, straight lines or other linearforms. The result of a corresponding arrangement and formation is acombined optical effect, which for example on the one hand collectslight and on the other hand deflects the light completely in onedirection, depending on the form of the elements. By a correspondingarrangement, therefore, an image is not projected x times correspondingto the number of elements, but all elements together preferably resultin only one projection.

Though other processing techniques are also possible,in a preferredembodiment of the present invention, it is provided that thelight-directing structure or optical prism is printed onto the substratein a matrix printing method, and in particular an inkjet printingmethod. In particular, a DOD inkjet printer (“Drop on Demand” inkjetprinter) is used, i.e. the inkjet printer places individual applicationson the substrate in the form of droplets. In particular, the ink ispressed through a printer nozzle by means of piezo elements.

In a preferred embodiment, it is provided that the light-directingstructures or optical microstructures have a glare-reducing effect, inthat they deflect incident daylight or light from another light sourcein such a way that the observer does not look into the beam path.

The light-directing and in particular glare-reducing effect can besupplemented by a motif which represents, for example, the picture of alandscape, an object or similar. Logos or alphanumeric symbols, whichcan be used for advertising or information purposes, are also possibleas motifs. These symbols can be made detectable either by the opticalstructure or by corresponding colouring. A light-directing andglare-reducing device can be especially advantageously implemented sothat the lower light-directing elements direct incident light stronglyupward in a bundled form, whereas the upper light-directing elementsdirect incident light into the depth of the room in a flatly bundledform, so that an even distribution of scattered light in the room isgenerated. Targeted projection of a coloured logo, symbol or writing isalso possible. This formation can then be provided, for example, on acorresponding window pane or similar.

According to a preferred embodiment of the present invention, it isprovided that the applications (namely the particles, droplets and/orstrips) are sufficiently small that they would provide at least about1200 to 2000 droplets per each 25.4 mm in length of a line. Furthermore,it is provided that the applications have a resolution of 1200 to 2000dpi, corresponding to an arrangement of preferably 1200 to 2000 dropletsor other application deposits on a 25.4 mm long line, and/or a number of50 to 80 droplets per millimetre of length. More preferably, theapplications have a resolution of 1,600 dpi. Also, it is preferablyprovided that the applications are formed from a material quantity of0.1 to 32 picolitres, and in particular 2 to 32 picolitres.

According to a preferred embodiment of the present invention, it isprovided that the light-directing structure and/or at least one elementhas a distribution of particles, droplets and/or strips which arearranged in a series of repeating patterns that progressively radiatefrom a common central region; for example, the pattern may progressivelyradiate circularly in concentric rings, the radially outermost of saiddroplets having the greatest diameter and the central ones having thesmallest diameter, to form a structure of a divergent lens type, or theradially outermost of said particles, droplets and/or strips having thesmallest diameter and the central ones having the greatest diameter, toform a structure of a convergent lens type. A combination of the abovemay also be employed.

According to a preferred embodiment of the present invention, it isprovided that the light-directing structure and/or at least one elementhave multiple rows of particles, droplets and/or strips which arearranged parallel to each other, and the radius or thickness of which ina row are equal or unequal and in a column are unequal or equal, to forma prism-like structure, the particles, droplets and/or strips of a rowof particles, droplets and/or strips following the adjacent rowpreferably being positioned on a gap or offset relative to the precedingrow.

According to a preferred embodiment of the present invention, it isprovided that each element has rows or rings of particles, dropletsand/or strips of different sizes, alternately if appropriate, so that aFresnel-like structure is formed.

According to a preferred embodiment of the present invention, it isprovided that the material which forms the particles, droplets and/orstrips is a printing ink of an inkjet printing ink type, which ispreferably colourless, coloured and/or mixed with functional and inparticular filter material (e.g., particles). Because of the admixtureof functional material such as filter or polarisation particles, thelight-directing structure comprises, as well as the light-directingfunction, a light-modifying function, by which, for example, the lightbeams are filtered and/or polarised. Preferably, the particles, dropletsand/or strips are made of a material that can be or is liquefied orsubstantially “atomized” for depositing through a printhead, andthereafter be dried, hardened and/or cured to a substantially hardenedstate that assumes and retains the desired shape of the particles,droplets and/or strips. Desirably the material and the processingconditions are selected so that each successive deposit bonds to thesubstrate and to an adjoining deposit, while still preserving thedesired size and shape intended. For this purpose, it has been foundthat a transparent printing ink may be employed, such as a UV-curingink, a solid ink and/or a gel ink. Advantageously, the printing ink canbe cured by means of UV radiation. According to choice, each droplet iscured individually by UV radiation directly after printing, or multipleparticles, droplets and/or strips are printed on first, and are thencured together by UV radiation. This has the advantage that the variousparticles, droplets and/or strips can be joined to each other beforecuring.

What is also achieved by the corresponding printing ink is thatcorresponding particles, droplets and/or strips can easily be depositedin a corresponding quantity on the substrate, in which case fast dryingof the droplets is achieved, in particular if gel ink is used, so thatexact and permanent formation of the corresponding elements andstructures is ensured. Such solid inks or gel inks are known in theprior art. It can also be provided that the printing ink is colourless,or fully or partly translucently coloured.

According to a preferred embodiment of the present invention, it isprovided that the light-directing structure and/or at least one elementis covered with a clear lacquer and/or finisher, which preferably formsa substantially planar surface of the light-directing structure and/orelement. Such a finisher or clear lacquer homogenises the surface of theindividual light-directing structures, which are formed of droplets,without changing the character of the generated structures, so thatundesired light refractions are minimised. The clear lacquer and/orfinisher preferably comprises a highly viscous material, which inparticular comprises a material which wets the applications, the clearlacquer and/or finisher preferably being mixed with functionalparticles, and more preferably with filter particles. In particular, theclear lacquer and/or finisher consists of the same transparent materialas the applications.

According to a preferred embodiment of the present invention, it isprovided that the substrate is a sheet of a preferably clear material,for example glass or artificial glass. It can also be provided that thesubstrate is an at least partially, if not entirely, transparent plasticbody (e.g., a film). The plastic may include a polymer, such as athermoplastic polymer, that is substantially entirely amorphous. By wayof example, it may include one or more of an acrylic, a polycarbonate, apolyester (e.g., polyethylene terephthalate), polyamide, a polyolefin, asilicon containing polymer or any combination thereof. Such a body(e.g., a film) can, for example, be implemented in self-adhesive form,and thus be attached to any transparent surfaces. Such a film can alsobe made in non-adhesive form, e.g. in the form of a roller blind whichcan be rolled up, or used as a film for visual privacy and protectionfrom glare. The size of the whole light-directing and/or glare-reducingdevice can vary according to where it is used, depending on whether, forexample, a small sub-pane or a large display window is equipped with thecorresponding version.

Alternatively, corresponding devices can also be provided as part of apublication, or they can be part of a visual aid.

According to a preferred embodiment of the present invention, it isprovided that the device comprises a specimen device produced in a“rapid prototyping” process. Advantageously, a specimen device which canbe produced easily and inexpensively, and on the basis of whichspecified optical properties can be checked, is provided. For example,it is conceivable that a specimen device is produced depending on a setof theoretically calculated optical parameters to characterise a Fresnelstructure. The set of theoretically calculated optical parameters canthen be checked or optimised on the basis of actually measured opticalmeasurement data of the actual specimen device. This is done bycorresponding measurement of the specimen device, so that fast,inexpensive iterative optimisation of the optical parameters is madepossible.

The present invention also relates to an illustration element, which hasa device according to the invention, the illustration element having asubstrate element which is provided with a printed image, and which isjoined to the device in such a way that the substrate element, and inparticular the printed image, are at least partly covered by the device.The printed image comprises, in particular, a motif, specified opticaleffects being generated by the device when the motif is observed. Inparticular, the device is adjusted to the motif in such a way that onlythe optical appearance of partial areas of the motif is correspondinglymodified by the device. The motif can be produced by means oftransparent or non-transparent printing ink according to choice.

According to a preferred embodiment of the present invention, it isprovided that the illustration element comprises a printed image whichis printed on the substrate, and which is preferably arranged betweenthe substrate and the light-directing structure or on a side of thesubstrate facing away from the light-directing structure. Morepreferably, it is provided that the printed image is producedsimultaneously with the printing of the light-directing structure. Theproduction process of the illustration element is thus made considerablyfaster.

According to a preferred embodiment of the present invention, it isprovided that the illustration element comprises a billboard, a poster,a decorative surface, a cladding element, a facade cladding, a brochureor periodical page, a cover sheet, a picture, a packaging (e.g. a foodpackaging), a label, a house number, a window image, a screen, alampshade, a diffusing screen, an adhesive label, a plate, a computerscreen and/or similar.

The present invention also relates to a method of producing a deviceaccording to the invention, wherein in a first production step thesubstrate is prepared, and in a second production step a transparentmaterial is arranged on the subject, and preferably printed onto thesubstrate by a printing method, in such a way that the light-directingstructure is generated in the form of the at least one optical prism.Advantageously, the method according to the invention makes possibleparticularly inexpensive, fast production of the device for directinglight beams. This is achieved by the light-directing structure beinggenerated in a printing process by the at least one optical prism whichis printed on the substrate, or by multiple optical prisms which areprinted on the substrate. The substrate is, in particular, translucentand/or transparent, the light-directing structure preferably beingprinted on one or both sides of the substrate. In the second productionstep, preferably an optical lens and in particular a Fresnel structureare produced from multiple optical prisms, which are formed bysimultaneous or sequential printing of the multiple optical prisms ontothe substrate. Alternatively to the described printing method, also alayer of the transparent material could be deposited on the substrateand then etched or otherwise treated to remove material in the layer ofthe transparent material in order to generate the light-directingstructure in the form of the at least one optical prism.

According to a preferred embodiment of the present invention, it isprovided that in a first substep of the second production step, multipleapplications are printed onto the substrate, in a second substep of thesecond production step the applications are cured, in a third substep ofthe second production step further applications are printed onto thesubstrate, and in a fourth substep of the second production step thefurther applications are cured, and to generate the light-directingstructure in particular the first, second, third and/or fourth substepsare repeated several times. The light-directing structures are thusformed by multiple applications, which are printed simultaneously orsequentially onto the substrate, and then cured. The curing process iscarried out in the third and/or fourth substep by irradiation withelectromagnetic radiation, in particular ultraviolet radiation, theradiation preferably being focused on the applications to be curedand/or further applications. The further applications are arranged inthe third substep parallel to the plane of principal extension of thesubstrate next to the applications, and/or perpendicularly to the planeof principal extension of the substrate on the applications, so that anythree-dimensional structures can be built from the applications andfurther applications.

According to a preferred embodiment of the present invention, it isprovided that the second production step, and in particular the firstand/or third substep, are carried out by a printing method, preferablyan inkjet printing method, so that production of the device isparticularly inexpensive. More advantageously, to carry out the firstand/or third substep, standard inkjet printing methods are used.Preferably, the applications and/or further applications are placed onthe substrate in the first and/or third substep by means of a printhead, which is moved automatically, and in particular under softwarecontrol, over the substrate. Thus the device to be produced can bedesigned in a way which is particularly precise and user-friendly andcan be stored by means of corresponding software, and in particular theoptical properties of the light-directing structure to be achieved canbe selected by means of the software. The surface of the substrate ispreferably divided into a virtual matrix, the desired positions of theindividual applications and/or further applications on the substratebeing converted into matrix co-ordinates of the virtual matrix, and theprint head being moved over the substrate in such a way that theapplications and/or further applications are printed onto the substratedepending on the current matrix co-ordinates. The radii of theapplications and/or further applications are more preferably setdepending on the matrix co-ordinates, in particular the quantity of thetransparent material to be applied at a desired position on thesubstrate being set depending on the application parameters. Theapplication parameters are, for example, linked to the matrixco-ordinates in such a way that to produce a device with a specifiedoptical property, only the matrix co-ordinates and the applicationparameters must be set correspondingly. This is done using the software,so that the production information can easily be modified, stored andreplaced. The production information can also conceivably be dispatched,so that the device can be designed and produced in different places.

According to a preferred embodiment of the present invention, it isprovided that the method of producing a specimen device is carried out,in particular, as part of a “rapid prototyping” process, the matrixco-ordinates and/or application parameters preferably being determinedautomatically from optical, CAD and/or image data. In this connection,it is conceivable that to produce a device with specified opticalproperties, the matrix co-ordinates and application parameters aremodified alternately on the computer, and then a specimen device isproduced for assessment of the modifications carried out on thecomputer. In this way, an iterative optimisation method for optimisingthe optical properties of the device can be carried out.

According to a preferred embodiment of the present invention, it isprovided that optical parameters of a light-directing structure to beproduced are prepared in particular with software support, the requiredmatrix co-ordinates and/or application parameters for producing such alight-directing structure being determined automatically from theoptical parameters, which preferably comprise the focal length, lensdiameter, spherical parameters, refractive indices and/or lens thicknessof a Fresnel lens. More advantageously, it is provided that only theoptical parameters to be achieved are specified, and the matrixco-ordinates and application parameters are automatically calculatedfrom them. In this way, for example, special lenses could be producedautomatically, only the optical parameters of the special lens to beproduced being previously entered into a corresponding computer program.

According to a preferred embodiment of the present invention, it isprovided that the print head is moved over the substrate in such a way,depending on the matrix co-ordinates and/or application parameters, thatthe travelled distance and/or the deposition duration to apply thetransparent materials are minimised. Thus, advantageously, minimisationof the production time to produce the device is achieved.

According to a preferred embodiment of the present invention, it isprovided that in the second production step, and in particular in thefirst and/or third substep, applications and/or further applications inthe form of droplets, particles and/or strips of transparent materialare arranged on the substrate, the transparent material preferably beinga transparent printing ink such as an inkjet printing ink, which morepreferably is colourless or coloured, and/or which more preferablycomprises a UV-curing ink. Preferably, in the first and/or thirdsubstep, applications and/or further applications with differentdiameters are arranged on the substrate, the radius in each casepreferably being set by the quantity of applied printing ink.Alternatively, it is conceivable that to enlarge an application whichwas arranged on the substrate in the first substep, in the third substepa further application is arranged on the application, the second substepselectively being carried out or omitted between the first and thirdsubsteps. In this case the further application is arranged on theapplication, so that at this place, for example, either the result is asingle droplet with an enlarged diameter (omission of the secondsubstep) or two droplets are stacked one on top of the other (the secondsubstep being carried out between the first and third substeps).

According to a preferred embodiment of the present invention, it isprovided that in the second production step, an element which is formedfrom multiple applications and further applications is generated.Preferably, in the second production step multiple elements, whichtogether form the light-directing structure, are applied next to eachother. Advantageously, in this way, for example multiple elements, whichafter completion jointly form the light-directing structure, are printedon simultaneously. The printing method can be optimised in this way. Inparticular, it is conceivable that for all elements, droplets withconstant radius are printed. For example, first all droplets of a firstdiameter are printed on (for all elements), then all droplets of asecond diameter are printed on (again for all elements), and so on.

According to a preferred embodiment of the present invention, it isprovided that in a third production step a finisher and/or a clearlacquer is applied to the light-directing structure and/or to at leastone element, the surface of the light-directing structure and/or of theat least one element preferably being made planar, and in particularsmoothed. Thus, advantageously, the surface of the light-directingstructure is protected and made smooth, without the desired opticalproperties being affected.

To be able to apply corresponding light-directing structures easily to asubstrate, it is proposed that transparent or translucent printing inkin droplet form is applied to the substrate by inkjet printing, thatdroplets of equal and/or unequal size are applied to generateminiaturised light-directing elements, and that multiple such elementsare applied next to each other, and together form the light-directingstructure such as a prism or lens.

It can be provided that droplets of different diameter are applied, thediameter being determined by the applied quantity of printing ink. Itcan also be provided that droplets of different diameter are formed byapplying printing ink in a quantity of 0.2 to 32 picolitres, preferably2 to 32 picolitres. It can also be provided that the droplets ofdifferent diameter are formed by printing ink for forming a smalldroplet being applied once, and for forming a larger droplet beingapplied several times at the same place.

It can also be provided that the droplets are deposited at a resolutionof 1200 to 2000 dpi, and preferably 1200 to 1600 dpi, on the substrate,next to each other, touching each other if required, and/or over eachother, in particular overlapping each other.

According to a preferred embodiment of the present invention, it isprovided that the way the applications or light-directing pixels(droplets) are formed is that in one position, transparent printing inkis applied once or more times, and thus, by different quantities ormultiple applications at one place, different heights of applications onthe substrate, or of transparent particles on the transparent material,are formed. In this way, for example, virtual mini-prisms or mini-lensescan be represented, and can deflect the light passing through themdifferently. The droplet size for pixel formation must be provided andadjusted by the calculation programs which are known for standard inkjetprinters. The pixel and the whole plane can be designed from standardoptical calculation programs, which for example produce a data set as acolour model, corresponding to a printed image for the differentgeometries in the plane. Each plano-convex pixel preferably represents adifferent optical effect. By colour settings, for example from the CYM,RGB or CMYK system, this printed image can be directly exploited by thesoftware of digital printers, if the printers print transparent inkinstead of the three colours cyan, yellow and magenta (or red greenblue).

Of course, the known calculation programs can also be combined so thatthe direct result is a modified data set. The known printers can also bemodified so that they work with only a transparent printing ink from areservoir. It is also possible to use a combination of the knownprinting inks and transparent printing ink, to create printed imageswith partial optical systems. So that the transparent ink does notpenetrate too deeply into the surface of the material to be printed on,but as far as possible remains completely on the surface, it should befast drying. Gel-like inks or solid inks are more advantageous for thispurpose. The droplets of different sizes, individually or overlaid,result in optical elements which have radii or asymmetrical curves,which in turn can be combined into complex light-refractingmicrostructures.

It can also be preferably provided that the droplets to generate anelement are deposited circularly in concentric rings, of which theradially outermost are deposited with the greatest diameter and thecentral ones are deposited with the smallest diameter, so that adivergent lens structure is formed, or in the reverse arrangement, sothat a convergent lens structure is formed.

Alternatively, it can be preferably provided that the droplets togenerate each element are deposited in multiple mutually parallel rows,the thickness or diameter of which in a row is equal or unequal, and ina column is unequal or equal, to form a prism-like structure.

It can also be alternatively provided that the droplets to generate eachelement are deposited in rows or circles in different sizes, alternatelyif appropriate, so that a Fresnel-like structure is formed.

It can also be provided that a finisher or clear lacquer is applied toeach element, or to the whole structure formed from many elements, tosmooth the surface. In this way, preferably homogenisation of thesurface is achieved, without changing the light-directing property ofthe structures. Only undesired light refractions are preferablyminimised in this way. The surface of the light-directing structure isalso protected from external environmental influences.

It can also be provided that the substrate and/or the printing ink isentirely or partly translucently coloured.

It can also be provided that parts of the whole structure are puttogether from light-directing and non-light-directing elements. Forexample, it is conceivable that the non-light-directing structurecomprises a support structure and/or a screen.

Embodiments of the invention are shown in the drawings, and explained inmore detail in the following description.

DESCRIPTION OF FIGURES

FIG. 1 is a schematic perspective view of a device according to a firstembodiment of the present invention,

FIG. 2 is a schematic perspective view of an optical prism of a deviceaccording to a second embodiment of the present invention,

FIG. 3 is a schematic sectional view of an optical prism of a deviceaccording to a third embodiment of the present invention,

FIGS. 4 a, 4 b are a schematic sectional view and a schematic plan viewof an optical prism of a device according to a fourth embodiment of thepresent invention,

FIGS. 5 a, 5 b are schematic views of a light-directing structure of adevice according to a fifth embodiment of the present invention,

FIGS. 6 a, 6 b are schematic views of a light-directing structure of adevice according to a sixth embodiment of the present invention,

FIG. 7 is a schematic plan view of a light-directing structure of adevice according to a seventh embodiment of the present invention,

FIG. 8 is a schematic plan view of a device according to an eighthembodiment of the present invention,

FIG. 9 is a perspective view of a device according to a ninth embodimentof the present invention,

FIG. 10 is a perspective view of a device according to a tenthembodiment of the present invention,

FIG. 11 is a sectional view of different light-directing structures of adevice according to an eleventh embodiment of the present invention,

FIG. 12 is a sectional view of a light-directing structure of a deviceaccording to a twelfth embodiment of the present invention,

FIGS. 13 a, 13 b are schematic views of devices according to thirteenthand fourteenth embodiments of the present invention,

FIGS. 14, 15, 16 are views of light-directing structures of a deviceaccording to fifteenth, sixteenth and seventeenth embodiments of thepresent invention,

FIGS. 17, 18 are schematic views of devices according to eighteenth andnineteenth embodiments of the present invention.

EMBODIMENTS OF THE INVENTION

The following applies to the entirety of the teachings herein. Anynumerical values recited herein include all values from the lower valueto the upper value in increments of one unit provided that there is aseparation of at least 2 units between any lower value and any highervalue. As an example, if it is stated that the amount of a component ora value of a process variable such as, for example, temperature,pressure, time and the like is, for example, from 1 to 90, preferablyfrom 20 to 80, more preferably from 30 to 70, it is intended that valuessuch as 15 to 85, 22 to 68, 43 to 51, 30 to 32 etc. are expresslyenumerated in this specification. For values which are less than one,one unit is considered to be 0.0001, 0.001, 0.01 or 0.1 as appropriate.These are only examples of what is specifically intended and allpossible combinations of numerical values between the lowest value andthe highest value enumerated are to be considered to be expressly statedin this application in a similar manner. Unless otherwise stated, allranges include both endpoints and all numbers between the endpoints. Theuse of “about” or “approximately” in connection with a range applies toboth ends of the range. Thus, “about 20 to 30” is intended to cover“about 20 to about 30”, inclusive of at least the specified endpoints.The disclosures of all articles and references, including patentapplications and publications, are incorporated by reference for allpurposes. The term “consisting essentially of to describe a combinationshall include the elements, ingredients, components or steps identified,and such other elements ingredients, components or steps that do notmaterially affect the basic and novel characteristics of thecombination. The use of the terms “comprising” or “including” todescribe combinations of elements, ingredients, components or stepsherein also contemplates embodiments that consist of or consistessentially of the elements, ingredients, components or steps. Pluralelements, ingredients, components or steps can be provided by a singleintegrated element, ingredient, component or step. Alternatively, asingle integrated element, ingredient, component or step might bedivided into separate plural elements, ingredients, components or steps.The disclosure of “a” or “one” to describe an element, ingredient,component or step is not intended to foreclose additional elements,ingredients, components or steps. References in the description toapplications such as “droplets” also encompasses particles and/orstrips. Unless stated otherwise, references to first, second, third,etc. Do not foreclose the presence of additional such items. N

In the various figures, like parts are invariably provided with likereference numerals and are therefore generally also named or mentionedonly once in each case.

FIG. 1 is a schematic perspective view of a device 100 for directinglight beams 3 according to a first embodiment of the present invention.The device 100 comprises a substrate 1, onto which a light-directingstructure 101 is printed by means of an inkjet printing method. Thelight-directing structure 101 consists of a transparent material in theform of a light-permeable, transparent and colourless printing ink whichis arranged on the substrate 1 by means of a printing head (not shown)and is then cured on the substrate 1 by irradiation of ultravioletradiation. The substrate 1 comprises, for example, a transparent plasticsheet, a transparent plastic sheet or a sheet of glass. The transparentmaterial is printed onto the substrate 1 in such a way that thelight-directing structure 101 comprises a plurality of optical prisms106. The optical prisms 106 each have a wedge-shaped cross-section 107.The substrate 1 has a plane of principal extension 105, the opticalprisms 106, of which a total of five are shown, being arranged inparallel in a plane parallel to the plane of principal extension 105.The optical prisms 106 each have a rectilinear configuration in thepresent example. Alternatively the optical prisms 106 may each have acurved configuration in the plane of principal extension 100. Eachoptical prism 106 has functional face 108 which is formed on a side ofthe optical prism 106 facing away from the substrate 1 perpendicularlyto the plane of principal extension 105 and which is inclined to theplane of principal extension 105 by an angle 109 in each case.Preferably, the angles 109 of adjacent optical prisms 106 have differentconfigurations, so as to produce a specific optical lens in the form ofa Fresnel structure. For this purpose, the angle 109 for example fromone side of the light-directing structure 101 to the other side of thelight-directing structure 101 (in a direction parallel to the plane ofprincipal extension 105 and perpendicular to the extension of theoptical prisms 106) could become increasingly small or great. Theoptical prisms 106 are preferably provided to deflect light beams 3 (notshown in FIG. 1), which pass through the device 100 perpendicularly tothe plane of principal extension 100, accordingly. The light beams 3 arethus broken as a function of their wavelengths and therefore spectrallyexpanded, for example on the functional face 108. Special opticaleffects, for example for advertising and/or illuminating purposes and/oras aids to vision, can be achieved in this way.

FIG. 2 is a schematic perspective view of an optical prism 106 of adevice 100 for directing light beams 3 according to a second embodimentof the present invention. FIG. 2 shows, by way of example, a detail ofone of the optical prisms 106 illustrated in FIG. 1, the optical prism106 being made up of a plurality of applications 102. In the presentexample, the applications 102 comprise individual droplets 2 of thelight-permeable, transparent and colourless printing ink, which havebeen printed individually onto the substrate 1 by the inkjet printer. Itcan be seen that the droplets 2 have different radii 104. The radii 104of the droplets 2 are greater on a broad side 110 of the wedge-shapedoptical prism 106 than on a narrow side 11 of the optical prism 106, soas to achieve the desired angle 109 between the functional face 108 andthe plane of principal extension 105. The individual applications 102are arranged both side by side and one above the other, in particular soas to overlap, on the substrate 1. The droplets 2 in this embodiment arearranged, for example, in mutually parallel rows 112 (see FIG. 4 b) ofequal droplet diameter 104, the radii 104 of two adjacent rows 112 beingdifferent. The droplets 2 in two adjacent rows 112 are, in particular,offset from one another in the longitudinal direction of the rows 112.After the arrangement and curing of the individual droplets 2, theoptical prism 106 or the entire light-directing structure 101 is coatedwith a finisher 7, in order to level the functional face 108 and protectthe droplets 2 from external environmental influences. The finisher 7preferably also comprises a light-permeable transparent material whichis preferably identical to the transparent material of the droplets 2.

FIG. 3 is a schematic sectional view of an optical prism 106 of a device100 for directing light beams 3 according to a third embodiment of thepresent invention. Similarly to FIG. 2, FIG. 3 shows by way of example adetail of one of the optical prisms 106 illustrated in FIG. 1, but incontrast to FIG. 2, all applications 102 have equal radii 104. In thisexample, the wide end 110 of the wedge-shaped optical prism 106 isformed by a plurality of superimposed droplets 2 of equal diameter 104,whereas only a single row 112 of droplets 2 is arranged in the region ofthe narrow end 111 (without superimposition).

FIGS. 4 a and 4 b are a schematic sectional view and a schematic planview of an optical prism 106 of a device 1 for deflecting light beams 3according to a fourth embodiment of the present invention, FIGS. 4 a and4 b showing an optical prism 106 which is constructed similarly to thatin FIG. 2 and is formed by droplets 2 of different radii 104 arranged inrows. It can be seen from the plan view in FIG. 4 b that the droplets 2in adjacent rows 112 are offset from one another and each have equalradii 104.

FIG. 5 b, 5 b are schematic views of a light-directing structure 101 ofa device 100 for directing light beams 3 according to a fifth embodimentof the present invention, the device 100 according to the fifthembodiment being formed from the optical prism 106, shown in FIG. 4 a,of the device 1 according to the fourth embodiment, the optical prism106 in contrast to the fourth embodiment being arranged, not as arectilinear structure, but as a concentrically curved structure in aclosed circle. The radii 104 of the droplets 2 each decrease steadilyoutwards from the centre of the light-directing structure 101 in aradial direction 114. The optical prism 106 therefore forms a convergentlens-like light-directing structure 113 in a plane parallel to the planeof principal extension 105.

FIG. 6 a, 6 b are schematic views of a light-directing structure 101 ofa device 100 for directing light beams 3 according to a sixth embodimentof the present invention, the sixth embodiment, similarly to the fifthembodiment illustrated in FIGS. 5 a and 5 b, being constructed from theoptical prism 106 shown in FIG. 4 a which, in contrast to the fourthembodiment, is also arranged not as a rectilinear structure but as aconcentrically curved structure in a closed circle, the radii of thedroplets 2, in contrast to the fifth embodiment, each increasingoutwards from the centre of the light-directing structure 101 in aradial direction 114. In this way, a divergent light-directing structure115 is constructed from the optical prism 106.

FIG. 7 is a schematic plan view of a light-directing structure 101 of adevice 100 according to a seventh embodiment of the present invention,the seventh embodiment having the convergent lens-like light-directingstructure 113, illustrated in FIGS. 5 a and 5 b, of the device 1according to the fourth embodiment, the convergent lens-likelight-directing structure 113 additionally being surrounded by a furtheroptical prism 106′. The further optical prism 106′ extendsconcentrically round the convergent lens-like light-directing structure113 in the plane parallel to the plane of principal extension 105. AFresnel structure comprising a comparatively great optical convergentlens with a reduced overall height perpendicular to the plane ofprincipal extension 105 is produced in this way. The angle 109 of theoptical prism 106 and of the further optical prism 106′ preferablydiffer, to minimise aberrations of the convergent lens. The arcuatelines 116 are merely intended to demonstrate schematically that theoptical prism 106 and the further optical prism 106′ are configured ascircles which are closed in on themselves in the plane parallel to theplane of principal extension 105.

FIG. 8 is a schematic plan view of a device 100 for directing lightbeams 3 according to an eighth embodiment of the present invention, theeighth embodiment being substantially identical to the sixth embodimentillustrated in FIG. 7, the convergent lens-like light-directingstructure 113 in the present example being surrounded by multiplefurther optical prisms 106′ (each indicated schematically by theconcentrically hollowed ring portions 116), so as to produce acomparatively great convergent lens in the form of a Fresnel structure.The light-directing structure 101 is further formed merely in partialregions corresponding to the sequence of letters “Lux” in a planeparallel to the plane of principal extension 105. No optical prisms 106are arranged outside these partial regions. Light beams 3 which now passperpendicularly to the plane of principal extension 100 through thisdevice 100 are bundled by the light-directing structure 101 in the formof the word “Lux”. It is therefore possible, for example, to project theword “Lux” onto a projection surface (for example an advertising wall),without the need for a screen. This could be used, for example, foradvertising and/or information purposes. The printing process whenprinting the applications 102 can be modified in such a way that thefocal length of the Fresnel structure is optimised to a distance betweenthe light-directing structure 101 and the projection surface, so that animage “Lux” which is as well-defined as possible is formed on theprojection surface. The device 100 illustrated in FIG. 8 is preferablypart of an illustration element 200, a motif additionally being printedonto the substrate 1. In this embodiment, the motif is preferablyprinted on a side of the substrate 1 facing the light-directingstructure 101 and preferably comprises, for example, the word “Lux”,which is applied to the substrate 1 with coloured but transparent ink.The motif and the light-directing structure 101 are preferably printedonto the substrate 1 in the same printing process.

FIGS. 9 to 18 are schematic views of devices 100 for directing lightbeams 3 according to ninth to eighteenth embodiments of the presentinvention. The devices 100 for directing light beams 3 each consist of alight-permeable, preferably transparent planar substrate 1, on one sideof which light-directing structures 101 are formed in the presentembodiments. These light-directing structures 101 consist of multipleminiaturised elements 103, of the type shown in various embodiments, forexample, in FIGS. 9 and 10 and in FIG. 11, the light-directingstructures 101 each comprising, in particular, at least one element inthe form of an optical prism 106. Each element 103 consists of multipledroplets 2 which are deposited on the substrate 1 with a planarperiphery so that they almost form a plane-convex element which has ahemispherical shape and projects from the substrate 1. As shown inparticular in FIGS. 9 to 12, 14, 15 and 16, the droplets 2 havedifferent radii 104, so that each element 103 forms, with the multipledroplets 2, for example a miniaturised partial prism, as shown in FIG.9, middle of FIG. 10, FIG. 12 and FIGS. 14 to 16, or a partial lens, asshown, for example, on the right of FIG. 10 and FIG. 11. The droplets 2preferably consist of light-permeable or even coloured transparent ortranslucent material.

As shown in particular in FIGS. 13 a, 13 b and 18, the multiple elements103 are preferably deposited side by side on the substrate 1 in such away that they together form a common light-directing structure 101 inthe form of a prism, a lens or a Fresnel structure. This allows, forexample in the embodiment according to FIG. 13 b, deflections of thelight beams 3 through the light-directing structures 101, so that theyare brought together to a point corresponding to the beam path 4 in themanner of a convergent lens. In the embodiment according to FIG. 13 a,the incident light is deflected upwards, for example by prismaticstructures, to the ceiling 5 of the room equipped with the correspondingwindow. In the configuration according to FIG. 18, correspondinglight-directing structures 101 are formed only in part on a substrate 1,free parts 6 not occupied by light-directing structures 101 beingprovided so that corresponding graphic representations can be seen.

All embodiments according to FIGS. 13 a, 13 b and 18 have the commonfeature that the elements 103 are deposited side by side on thesubstrate 1 in such a way that they together form a commonlight-directing structure 101 in the form of a prism, a lens or aFresnel structure.

Preferably, the droplets 2 have a resolution of approximately 1200 to1600 dpi, corresponding to an arrangement of about 1200 to 1600 dropletson a one inch long line or a number of 50 to 60 droplets per mm length.The droplets are preferably formed from a quantity of material ofapproximately 2 to 32 picolitres. Each element 103 can have adistribution of circular concentric rings of droplets 2, of which theradially outer droplet has the greatest radius 104 and of which themiddle one has the smallest radius 104, so as to form a divergent lens.Alternatively the radially outer droplets 2 have the smallest radius 104and the middle ones have the greatest radius 104, so as to form aconvergent lens-like structure. Other structures 101, for exampleprismatic structures or else Fresnel structures, can also be formed byan arrangement in a different sequence and size. The material formingthe droplets 2 is a printing ink of the inkjet printing ink type, solidink or gel ink preferably being used. The printing ink is preferablycolourless or else completely or partially translucent in colour. Asshown in FIG. 11, each miniaturised element 103 formed from the droplets2 is covered with clear lacquer or finisher 7 so as to form asubstantially plane surface of the element 103 or the structure 101,without changing the nature of the structure. Homogenisation of thesurface is thus achieved, without changing the light-directing effect.Only divergent light is substantially avoided in the process. Thecorresponding clear lacquer or finisher 7 consists of high-viscositymaterial, so that the indentations formed by the droplets 2 arecompletely filled and a homogeneous surface is produced. The substrate 1can be a clear sheet of glass or artificial glass. It is also possibleto provide a transparent film of plastic as the substrate, as shown inFIG. 18. The corresponding structures are produced by applyingtransparent or translucent printing ink in droplet form to the substrate1 by inkjet printing, so that droplets 2 of equal and unequal size areapplied for the production of miniaturised light-directing elements 103.A plurality of elements 103 of this type are arranged side by side,optionally passing into one another, and together form thelight-directing structure 101, for example a prism or a lens. Thedifferent radii 104 of the droplets 2 can be determined bycorrespondingly different quantities of the respectively appliedprinting ink. It is also possible to form the droplets 2 of differentdiameters 104 by applying printing ink for forming a small droplet 2once and for forming a larger droplet 2 multiple times at the sameposition. Preferably, the droplets are each arranged side by side inmutual contact, as shown in particular in FIG. 15, although somedistance can also be provided between adjacent droplets 2, as shown inFIG. 14.

As shown in FIG. 17, the substrate 1 can also be the glass of an aid tovision, to which the corresponding structures are applied in the form ofthe droplets 2, in order to produce a corresponding aid to vision of acorresponding prescription.

The invention is not limited to the embodiments, but can be variedwidely in the scope of the disclosure. Any new individual or combinedfeatures disclosed in the description and/or drawings are deemed to beessential to the invention.

It is understood that the above description is intended to beillustrative and not restrictive. Many embodiments as well as manyapplications besides the examples provided will be apparent to those ofskill in the art upon reading the above description. The scope of theinvention should, therefore, be determined not with reference to theabove description, but should instead be determined with reference tothe appended claims, along with the full scope of equivalents to whichsuch claims are entitled. The disclosures of all articles andreferences, including patent applications and publications, areincorporated by reference for all purposes. The omission in thefollowing claims of any aspect of subject matter that is disclosedherein is not a disclaimer of such subject matter, nor should it beregarded that the inventors did not consider such subject matter to bepart of the disclosed inventive subject matter.

LIST OF REFERENCE NUMERALS

1 substrate

2 droplets

3 light beams

4 beam path

5 ceiling

6 free parts

7 finisher

100 device

101 light-directing structure

102 applications

103 elements

104 radius of applications

105 plane of principal extension

106 optical prism

107 cross-section of optical prism

108 functional face of optical prism

109 angle between functional face and plane of principal extension

110 wide side of optical prism

111 narrow side of optical prism

112 rows of applications

113 convergent lens-like light-directing structure

114 radial direction

115 divergent lens-like light-directing structure

116 ring portions

200 illustration element

1. Device (100) for directing light beams, comprising a translucentsubstrate (1), and a light-directing structure (101) on at least aportion of the substrate (1), characterised in that the light-directingstructure (101) comprises a substantially transparent material, which isarranged in a pattern on the substrate (1) in such a way that thelight-directing structure (101) comprises at least one optical prism(106).
 2. Device (100) according to claim 1, characterized in that thelight-directing structure (101) is printed onto the substrate (1) insuch a way that the light-directing structure (101) comprises at leastone optical prism (106).
 3. Device (100) according to one of the claim 1or 2, characterised in that the light-directing structure (101)comprises an optical lens, and in particular a Fresnel structure, whichis formed from the at least one optical prism (106), and in particularfrom multiple optical prisms (106).
 4. Device (100) according to claims1 to 3, characterised in that the light-directing structure (101)comprises multiple applications (102) which are printed onto thesubstrate (1), and which consist of the transparent material.
 5. Device(100) according to claim 4, characterised in that the applications (102)are preferably arranged side by side or one above the other in a planeparallel to the plane of principal extension (105) of the substrate (1).6. Device (100) according to either claim 4 or claim 5, characterised inthat the applications (102) comprise particles of the transparentmaterial, droplets (2) of the transparent material and/or linearlyformed strips of the transparent material, the applications (102)preferably including droplets (2) of the transparent material which arecured by ultraviolet radiation.
 7. Device (100) according to claims 4 to6, characterised in that the multiple applications (102) have differentand/or substantially identical radii (104), in particular the opticalprism being formed of a plurality of applications (102) of differentradii (104) or from a plurality of applications (102) of identical radii(104).
 8. Device (100) according to any one of claims 4 to 7,characterised in that the applications (102) are placed on a planarperiphery of the substrate (1), the applications (102) preferably eachhaving an approximately hemispherical curvature, which projects from thesubstrate (1).
 9. Device (100) according to any one of the precedingclaims, characterised in that the optical prism (106) has at least onefunctional face (108) which is inclined relative to the substrate (1),and which in particular is formed on a side of the optical prism (106)facing away from the substrate (1) perpendicularly to the plane ofprincipal extension (105), two adjacent optical prisms (106) preferablyhaving different angles (109) between the respective functional face(108) and the plane of principal extension (105).
 10. Device (100)according to any one of claims 1 to 9, characterised in that thelight-directing structure (101) consists of multiple elements (103),each element consisting of multiple optical prisms (106) and/orapplications (102).
 11. Device (100) according to claim 10,characterised in that each element (103) forms a partial prism, apartial lens and/or another specific optical system, the elements (103)preferably being deposited or printed side by side or in each other onthe substrate (1), in such a way that the elements (103) together formthe light-directing structure (101) in the form of the Fresnelstructure, optical prism and/or optical lens.
 12. Device (100) accordingto any one of claims 4 to 11, characterised in that the applications(102) are sufficiently small that they would provide at least about 1200to 2000 droplets per each 25.4 mm in length of a line and/or that theapplications (102) have a resolution of 1200 to 2000 dpi, correspondingto an arrangement of preferably 1200 to 2000 droplets (2) on a 25.4 mmlong line, and/or a number of 50 to 80 droplets (2) per millimetre oflength, the applications (102) more preferably having a resolution of1600 dpi.
 13. Device (100) according to any one of claims 4 to 12,characterised in that the applications (102) are formed from an amountof material of 0.1 to 32 picolitres.
 14. Device (100) according to anyone of claims 4 to 13, characterised in that the light-directingstructure (101) and/or at least one element (103) comprises adistribution of applications (102) arranged circularly in concentricrings, the radii (104) of the applications (102) of a radially outerring being greater than the radii (104) of the applications (102) of aradially inner ring, in such a way that a divergent lens-likelight-directing structure (115) is formed.
 15. Device (100) according toany one of claims 4 to 14, characterised in that the light-directingstructure (101) and/or at least one element (103) comprises adistribution of applications (102) arranged circularly in concentricrings, the radii (104) of the applications (102) of a radially outerring being smaller than the radii (104) of the applications (102) of aradially inner ring, in such a way that a convergent lens-likelight-directing structure (113) is formed.
 16. Device (100) according toany one of claims 4 to 15, characterised in that the light-directingstructure (101) and/or at least one element (103) comprises a pluralityof rows (112) of applications (102) arranged in parallel, the radii(104) of the applications (102) along a row (112) being substantiallyequal or unequal and the radii (104) of the applications (102) ofdifferent rows being substantially unequal or equal, in such a way thata prism-like light-directing structure (101) is formed.
 17. Device (100)according to claim 16, characterised in that the applications (102) oftwo adjacent rows (112) are mutually offset in the longitudinaldirection.
 18. Device (100) according to any one of claims 4 to 17,characterised in that the light-directing structure (101) and/or atleast one element (103) have rows (112) or circular rings ofapplications (102) of different diameters (104) in such a way that aFresnel-like light-directing structure (101) is formed.
 19. Device (100)according to any one of claims 1 to 18, characterised in that thetransparent material is a transparent polymer and/or a transparentprinting ink of the inkjet printing ink type, which is preferablycolourless, coloured and/or mixed with functional and in particularfilter particles.
 20. Device (100) according to claim 19, characterisedin that the transparent printing ink is a UV-curing ink.
 21. Device(100) according to any one of claims 1 to 20, characterised in that thelight-directing structure (101) and/or at least one element (103) iscovered with a clear lacquer and/or a finisher (7), a substantiallyplanar surface of the light-directing structure (101) and/or the element(103) preferably being formed.
 22. Device (100) according to claim 21,characterised in that the clear lacquer and/or the finisher (7)comprises a high-viscosity material, which comprises in particular amaterial which wets the applications (102), the clear lacquer and/or thefinisher (7) preferably being mixed with functional particles, and morepreferably with filter particles.
 23. Device (100) according to eitherclaim 21 or claim 22, characterised in that the clear lacquer and/or thefinisher (7) consist of the same transparent material as theapplications (102).
 24. Device (100) according to any one of claims 1 to23, characterised in that the substrate (1) is a sheet of clearmaterial, glass or artificial glass and/or the substrate (1) is atransparent film of plastics material.
 25. Device (100) according to anyone of claims 1 to 24, characterised in that the device (100) comprisesa specimen device produced in a “rapid prototyping” process. 26.Illustration element (200) comprising a device (100) according to anyone of claims 1 to 25, characterised in that the illustration element(200) comprises a substrate element which is provided with a printedimage, and which is joined to the device (100) in such a way that thesubstrate element, and in particular the printed image, are at leastpartly covered by the device (100).
 27. Illustration element (200)comprising a device (100) according to any one of claims 1 to 25,characterised in that the illustration element (200) comprises a printedimage which is printed on the substrate (2), and which is preferablyarranged between the substrate (2) and the light-directing structure(101) or on a side of the substrate (2) facing away from thelight-directing structure (1).
 28. Illustration element (200) accordingto either claim 26 or claim 27, characterised in that the illustrationelement (200) comprises a billboard, a poster, a decorative surface, acladding element, a facade cladding, a brochure or periodical page, acover sheet, a picture, a packaging, a label, a house number, a windowimage, a screen, a lampshade, a diffusing screen, an adhesive label, aplate, a computer screen and/or similar.
 29. Method for producing adevice (100) according to any one of claims 1 to 25, characterised inthat, in a first production step, the substrate (1) is prepared and inthat, in a second production step, a substantially transparent materialis arranged on the substrate (1), and preferably printed onto thesubstrate (1) by a printing method, in such a way that thelight-directing structure (101) is produced in the form of the at leastone optical prism (106).
 30. Method according to claim 29, characterisedin that, in the second production step, an optical lens, and inparticular a Fresnel structure, are produced from a plurality of opticalprisms (106).
 31. Method according to either claim 29 or claim 30,characterised in that, in a first substep of the second production step,a plurality of applications (102) are printed onto the substrate (1),the applications (102) being cured in a second substep of the secondproduction step, further applications (102) being printed onto thesubstrate (1) in a third substep of the second production step and thefurther applications (102) being cured in a fourth substep of the secondproduction step, in particular the first, second, third and/or fourthsubstep being repeated multiple times to produce the light-directingstructure (101).
 32. Method according to claim 31, characterised in thatthe third and/or the fourth substep are carried out by irradiation ofultraviolet radiation, which is preferably focussed onto theapplications (102) to be cured and/or further applications (102). 33.Method according to either claim 31 or claim 32, characterised in that,in the third substep, the further applications (102) are arrangedparallel to the plane of principal extension (105) of the substrate (1)beside the applications (102) and/or perpendicularly to the plane ofprincipal extension of the substrate (1) on the applications (102). 34.Method according to any one of claims 31 to 33, characterised in thatthe second production step, and in particular the first and/or thirdsubstep, are carried out by a printing method, preferably an inkjetprinting method.
 35. Method according to claim 34, characterised in thatthe applications (102) and/or further applications (102) are placed onthe substrate (1) in the first and/or third substep by means of a printhead, the print head being moved automatically, and in particular undersoftware control, over the substrate (1).
 36. Method according to claim35, characterised in that the surface of the substrate (1) is dividedinto a virtual matrix, the desired positions of the individualapplications (102) and/or further applications (102) on the substrate(1) being converted into matrix co-ordinates of the virtual matrix, andthe print head being moved over the substrate (1) in such a way that theapplications (102) and/or further applications (102) are printed ontothe substrate (1) as a function of the current matrix co-ordinates 37.Method according to claim 36, characterised in that the radii (104) ofthe applications (102) and/or further applications (102) are adjusted asa function of the matrix co-ordinates, in particular the quantity of thetransparent material to be applied at a desired position on thesubstrate (1) being adjusted as a function of application parameters,the application parameters being linked with the matrix co-ordinates.38. Method according to any one of claims 29 to 37, characterised inthat the method for producing a specimen device is carried out, inparticular, in a “rapid prototyping” process, the matrix co-ordinatesand/or the application parameters preferably being determinedautomatically from optical, CAD and/or image data.
 39. Method accordingto any one of claims 29 to 38, characterised in that optical parametersof a light-directing structure (1) to be produced are prepared inparticular with software support, the required matrix co-ordinatesand/or application parameters for producing such a light-directingstructure (1) being determined automatically from the opticalparameters, optical parameters preferably comprising the focal length,lens diameter, spherical parameters, refractive indices and/or lensthickness of a Fresnel lens.
 40. Method according to any one of claims35 to 39, characterised in that the print head is moved over thesubstrate (1) in such a way, as a function of the matrix co-ordinatesand/or application parameters, that the travelled distance and/or thedeposition duration to apply the transparent materials are minimised.41. Method according to any one of claims 31 to 40, characterised inthat in the second production step, and in particular in the firstand/or third substep, applications (102) and/or further applications(102) in the form of droplets, particles and/or strips of transparentmaterial are arranged on the substrate (1), the transparent materialpreferably being a transparent printing ink of an inkjet printing inktype, which more preferably is colourless or coloured, and/or which morepreferably comprises a UV-curing ink.
 42. Method according to any one ofclaims 31 to 41, characterised in that, in the first and/or thirdsubstep, applications (102) and/or further applications (102) withdifferent diameters (104) are arranged on the substrate (1), the radius(104) in each case preferably being set by the quantity of appliedprinting ink.
 43. Method according to any one of claims 31 to 42,characterised in that applications (102) and/or further applications(102) of different diameter are formed by application of printing ink ina quantity of 0.1 to 30 picolitres.
 44. Method according to any one ofclaims 31 to 43, characterised in that, to enlarge an application (102)which was arranged on the substrate (1) in the first substep, in thethird substep a further application (102) is arranged on the application(102), the second substep selectively being carried out or omittedbetween the first and third substeps.
 45. Method according to any one ofclaims 31 to 44, characterised in that the applications (102) aredeposited on the substrate (1) sufficiently small that they wouldprovide at least about 1200 to 2000 droplets per each 25.4 mm in lengthof a line and/or that the applications (102) are deposited at aresolution of 1200 to 2000 dpi on the substrate (1), side by side inmutual contact and in particular overlapping each other perpendicularlyto the plane of principal extension (105) of the substrate (1). 46.Method according to any one of claims 31 to 45, characterised in that inthe second production step, an element (103) which is formed frommultiple applications (102) and further applications (102) is generated.47. Method according to claim 46, characterised in that in the secondproduction step, multiple elements (103) are applied side by side, andtogether form the light-directing structure (101).
 48. Method accordingto any one of claims 31 to 47, characterised in that the applications(102) to generate the light-directing structure (101) and/or at leastone element (103) are deposited in substantially circular concentricrings, in such a way that the radii (104) of the applications (102) of aradially outer ring are greater than the radii (104) of the applications(102) of a radially inner ring, and a divergent-lens-likelight-directing structure (113) is formed.
 49. Method according to anyone of claims 31 to 48, characterised in that the applications (102) togenerate the light-directing structure (101) and/or at least one element(103) are deposited in substantially circular concentric rings, in sucha way that the radii (104) of the applications (102) of a radially outerring are smaller than the radii (104) of the applications (102) of aradially inner ring, and a convergent-lens-like light-directingstructure (115) is formed.
 50. Method according to any one of claims 31to 49, characterised in that in the second production step, theapplications (102) to generate the light-directing structure (101)and/or at least one element (103) are deposited in multiple rows (112)which are arranged parallel to each other, in such a way that the radii(104) of the applications (102) along a row are substantially equal orunequal, and the radii (104) of the applications (102) of different rows(112) are substantially unequal or equal, and a prism-likelight-directing structure (101) is formed.
 51. Method according to anyone of claims 31 to 50, characterised in that in the second productionstep, the applications (102) to generate the light-directing structure(101) and/or at least one element (103) are deposited in rows (112) orcircles with different diameters (104) alternately, in such a way that aFresnel-like light-directing structure (101) is formed.
 52. Methodaccording to any one of claims 31 to 51, characterised in that in athird production step a finisher (7) and/or a clear lacquer is appliedto the light-directing structure (101) and/or to at least one element(103), the surface of the light-directing structure (101) and/or of theat least one element (103) being preferably made planar, and inparticular smoothed.
 53. Method according to any one of claims 29 to 52,characterised in that the device (100) is put together from thelight-directing structure (101) and a non-light-directing structure. 54.Method of producing an illustration element (200) according to any oneof claims 26 to 28, characterised in that a method of producing a device(100) according to any one of claims 29 to 53 is carried out, wherein ina fourth production step, which in particular is carried out in timebefore the first production step and/or during the second productionstep, a printed image is printed onto the substrate (1), at least partlyopaque and/or coloured printing inks being used to produce the printedimage.
 55. Method of producing an illustration element (200) accordingto any one of claims 26 to 28, characterised in that a method ofproducing a device (100) according to any one of claims 29 to 53 iscarried out, wherein in a fifth production step a printed image isprinted onto a substrate element, and in a sixth production step thesubstrate element is joined to the device (100) in such a way that thesubstrate element, and in particular the printed image, are at leastpartly covered by the device (100).
 56. Method according to either 54 orclaim 55, characterised in that a billboard, a poster, a decorativesurface, a cladding element, a facade cladding, a brochure or periodicalpage, a cover sheet, a picture, a package, a label, a house number, awindow image, a screen, a lampshade, a diffusing screen, an adhesivelabel, a plate, a computer screen and/or similar are produced.